Method and apparatus for completing diverless subsea flowline connections

Abstract

A diverless subsea flowline connection system includes connectors for remotely connecting the ends of a first bundle of flowlines to the ends of a second bundle of flowlines and guidance components which direct the end portions of the first bundle of flowlines into precise connecting alignment with the end portions of the second bundle of flowlines without damage to the connecting seals. The ends of the first bundle are covered and sealed so that the flowlines can be pulled across the seafloor without damage to the ends of the flowlines. Means are provided for pulling the first bundle toward an alignment structure so that the lines can approach the structure from a wide variety of angles and the structure will guide the first bundle into exact alignment with the second bundle. This pulling means includes means for connecting a pulling cable to the radial center of a pulling head attached to the ends of the first bundle of flowlines. The ends of the flowlines are connected together and aligned before the fluid-tight seals are set to prevent possible damage to the seals. After the flowline ends are precisely aligned the seals are set. If desired, the connecting seals can be replaced by remote control. The pulling, aligning, replacement of seals and fluid-tight connecting of the flowlines is all done by remote control from the surface of the sea.

What is claimed is: 
     
       1. Remote-controlled apparatus for connecting a first connector, mounted on one end of a first flowline with a second connector mounted on one end of a second flowline and for securing the ends of the connectors in precise axial alignment without damage to seals used to interconnect the connectors, in a fluid-tight arrangement, said apparatus comprising: a pull-in cable;   means for connecting said pull-in cable to the geometric center of the free end of said first connector;   means for moving said pull-in cable and said first connector into axial alignment with said second connector;   an annular seal;   means for mounting said seal adjacent the free end of one of said first and second connectors;   means for securing the ends of said first and said second connectors in precise axial alignment without pressing the ends of said connectors against said seal; and   means for pressing the ends of said first and said second connectors against said seal in a fluid-tight relationship after the connectors are secured in precise axial alignment.   
     
     
       2. Remote-controlled apparatus for connecting as defined in claim 1 including means for moving the free end of said first connector into axially aligned engagement with the free end of said second connector. 
     
     
       3. Remote-controlled flowline connection apparatus for completing flowline connections, said apparatus comprising: a first connector mounted on one end of a first flowline;   a second connector mounted on one end of a second flowline;   a pull-in cable;   means for connecting said pull-in cable to the geometric center of said first flowline;   power means for moving said pull-in cable and said first connector toward said second connector;   a metal seal;   means for mounting said seal adjacent the free end of said second connector;   alignment means for guiding said first connector into axial alignment with said second connector as said first connector moves toward said second connector; and   means for clamping the ends of said first and said second connectors against said seal in a fluid-tight relationship.   
     
     
       4. Remote-controlled flowline connection apparatus as defined in claim 3 including means for securing said first connector in a fixed position after said first connector has been guided into axial alignment with said second connector. 
     
     
       5. Remote-controlled flowline connection apparatus as defined in claim 4 including means for disconnecting said pull-in cable after said first connector has been secured in a fixed position. 
     
     
       6. Remote-controlled flowling connection apparatus as defined in claim 5 including means for moving said second connector into axially aligned engagement with said first connector when said first connector is secured in said fixed position. 
     
     
       7. Remote-controlled flowline connection apparatus as defined in claim 6 including means for clamping said first and said second connectors in axially aligned engagement. 
     
     
       8. Remote-controlled flowline connection apparatus as defined in claim 7 including means for setting a fluid-tight seal between the end of said first and said second connectors after said first and second connectors have been clamped in axially aligned engagement. 
     
     
       9. Remote-controlled apparatus for connecting a first connector mounted on one end of a first flowline with a second connector mounted on one end of a second flowline, said apparatus comprising: a pull-in cable;   means for connecting said pull-in cable to the geometric center of the free end of said first connector;   means for mounting said second connector in a fixed position;   power means for moving said pull-in cable and said first connector toward said second connector;   a sealing member;   means for mounting said sealing member adjacent the free end of one of said first and said second connectors;   alignment means for guiding said first connector into axial alignment with said second connector as said first connector moves toward said second connector;   means for clamping the free ends of said first and said second connectors in precise axial alignment; and   means for pressing the ends of said first and said second connectors against said sealing member in a fluid-tight relationship.   
     
     
       10. Remote-controlled apparatus for connecting as defined in claim 9 wherein one of said first and said second connectors includes a recess adjacent the free end of said connector, said sealing member being stored in said recess until the free ends of said first and said second connectors are clamped together in precise axial alignment, and means for pressing said sealing member against the ends of said first and said second connectors to provide a fluid-tight seal. 
     
     
       11. Remote-controlled apparatus for connecting a first connector mounted on one end of a first flowline with a second connector mounted on one end of a second flowline, said apparatus comprising: a pull-in cable;   a protective cap;   means for mounting said protective cap over the free end of said first connector;   means for mounting said second connector in a fixed position;   an alignment funnel having a wide mouth portion and a narrower neck portion;   means for mounting said funnel with the neck portion adjacent the free end of said second connector;   means for moving said pull-in cable to pull said first connector into said funnel and align said first connector with said second connector;   sealing means;   means for removing said protective cap from the end of said first connector; and   means for setting said sealing means in a fluid-tight engagement between the ends of said first and said second connectors.   
     
     
       12. Remote-controlled apparatus as defined in claim 11 including means for pivotally mounting said funnel adjacent the free end of said second connector. 
     
     
       13. A method of connecting a flowline bundle hub to a flowline connector in a fluid-tight arrangement while preventing damage to the seals used to complete the connection, said method comprising the steps of: (1) mounting said seals on the end of said flowline connector,   (2) connecting a pull-in cable to the geometric center of the free end of said bundle hub,   (3) securing said flowline connector in a position with the free end of said flowline connector extending generally toward said bundle hub,   (4) pulling the geometric center of said bundle hub directly toward the geometric center of said flowline connector,   (5) securing the end of said bundle hub in precision alignment with the end of said flowline connector, and   (6) setting said seals in a fluid-tight engagement between the ends of said bundle hub and said flowline connector.   
     
     
       14. A method of connecting a flowline bundle hub to a flowline connector in a fluid-tight arrangement while preventing damage to the seals used to complete the connection, said method comprising the steps of: (1) mounting said seals in a recessed cavity in one of said bundle hub and said flowline connector to prevent damage to said seals as said bundle hub and said flowline connector are moved together,   (2) connecting a pull-in cable to the geometric center of the free end of said bundle hub,   (3) retaining said flowline connector in a position with the free end of said flowline connector extending generally toward said bundle hub,   (4) pulling the free end of said bundle hub toward the free end of said flowline connector,   (5) guiding the free end of said bundle hub into axial alignment with the free end of said flowline connector,   (6) securing the end of said bundle hub in precision alignment with the end of said flowline connector, and   (7) moving said seals outward from said cavity into a fluid-tight engagement between the ends of said bundle hub and said flowline connector.   
     
     
       15. A method of remotely controlling the movement of a pair of subsea flowline connectors into a fluid-tight arrangement while preventing damage to the seals used to complete the connection, said method comprising the steps of: (1) mounting said seals on the end of one of said flowline connectors,   (2) mounting a first connector in a fixed position relative to the seafloor,   (3) mounting a tapered guide means adjacent the free end of said first connector,   (4) connecting a pull-in cable to the geometric center of the free end of a second connector,   (5) pulling the free end of said second connector toward the free end of said first connector,   (6) guiding said free end of said second connector into axial alignment with said free end of said first connector,   (7) clamping the free end of said second connector to the free end of said first connector, and   (8) setting the seals in a fluid-tight engagement between the ends of said first and said second connectors.   
     
     
       16. Remote-controlled apparatus as defined in claim 11 wherein said alignment funnel includes a slot along the length of said funnel and wherein said apparatus includes means for moving said pull-in cable through said slot into the axial center of said funnel. 
     
     
       17. Remote-controlled apparatus for connecting a first connector mounted on one end of a first flowline with a second connector mounted on one end of a second flowline, said apparatus comprising: a pull-in cable;   means for connecting said pull-in cable to the geometric center of the free end of said first connector;   means for mounting said second connector in a fixed position;   an alignment funnel having a slot along the length of said funnel;   means for mounting said funnel with the small end of said funnel adjacent said second connector;   means for moving said pull-in cable through said slot to position said pull-in cable inside said alignment funnel;   means for moving said pull-in cable to pull said first connector into said funnel and align said first connector with said second connector; and   means for connecting the end of said first connector to the end of said second connector.   
     
     
       18. Remote-controlled apparatus as defined in claim 18 wherein said means for moving said pull-in cable through said slot includes means for mounting said funnel in a generally horizontal position with said slot running along the top portion of said funnel, and means for lowering said pull-in cable through said slot. 
     
     
       19. A protective cap for sealing the ends of a plurality of flowlines in a flowline connector and for releasably connecting said connector to a pull-in cable, said cap comprising: a generally cylindrical body member;   means for releasably securing said body member to the end of said flowline connector; and   means for releasably connecting said pull-in cable to said protective cap.   
     
     
       20. A protective cap is defined in claim 19 wherein said means for releasably securing said body member to said flowline connector includes: an annular connector flange at the end of said flowline connector;   an annular cap flange at the end of said protective cap;   a plurality of locking dogs; and   means for providing a radially inward pressure on both ends of each of said dogs to move said dogs astride both said connector flange and said cap flange to secure the end of said protective cap to the end of said flowline connector.   
     
     
       21. A protective cap as defined in claim 19 wherein said means for releasably connecting said pull-in cable includes means for remotely releasing and for remotely connecting said pull-in cable to said protective cap. 
     
     
       22. A protective cap as defined in claim 21 wherein said pull-in cable can be remotely connected and remotely disconnected from said protective cap while said protective cap is secured to said flowline connector. 
     
     
       23. A connector for connection to a cylindrical hub having an annular radial hub flange at the end of said hub, said connector comprising: a cylindrical body member;   an annular body sleeve slidably surrounding a portion of said body member, said sleeve having a radial sleeve flange at each end thereof;   a sealing member;   means for mounting said sealing member on a first end of said body member;   a plurality of connecting dogs mounted adjacent said sleeve flange at said first end of said body sleeve, each dog having first and second cam surfaces on the radially inward portion of said dogs;   means for providing a radially inward pressure on both ends of each of said dogs to force said first cam surface against said radial hub flange and force said second cam surface against said radial sleeve flange at a first end of said body sleeve to secure said first end of said body sleeve in precise axial alignment against the end of said cylindrical hub; and   means for moving said body member toward said cylindrical hub to compress said sealing member between the ends of said cylindrical hub and said body member after said body sleeve is in precise axial alignment with said cylindrical hub.   
     
     
       24. A connector as defined in claim 23 wherein said body member includes a radial body flange spaced from said first end of said body member, and wherein said means for moving said body member includes a plurality of sealing dogs mounted adjacent said radial body flange and said sleeve flange at a second end of said body sleeve and means for providing a radially inward pressure on both ends of said sealing dogs to move said sealing dogs against said body flange and against said second sleeve flange, said sealing dogs forcing said radial body flange toward said second sleeve flange. 
     
     
       25. A connector as defined in claim 23 including means for moving each of said dogs in a direct radially inward direction when a radial inward pressure is applied to the ends of said dogs. 
     
     
       26. A connector as defined in claim 23 wherein each of said dogs includes a cylindrical outer surface, means for positioning said cylindrical outer surface parallel to the axis of said body member prior to providing a radially inward pressure on the ends of said dogs, and means for retaining said outer surface in a position parallel to the axis of said body member as said dogs are moved radially inward. 
     
     
       27. A connector as defined in claim 23 including an actuation sleeve for providing said radially inward pressure on both ends of each of said dogs, said actuation sleeve including cylindrical inner surface means for pressing against the ends of said dogs to retain the dogs in a fixed position against said radial hub flange and against said radial sleeve flange when said dogs are at the extreme radial inward portion of their travel. 
     
     
       28. A connector as defined in claim 23 including an actuation sleeve for providing said radially inward pressure on both ends of said dogs, said actuation sleeve including means for pressing against the ends of said dogs to force said dogs radially inward as said actuation sleeve is moved axially parallel to the axis of said body member. 
     
     
       29. A connector as defined in claim 28 wherein said pressing means comprises a conical inner cam surface. 
     
     
       30. A connector as defined in claim 23 including an actuation sleeve for providing said radially inward pressure on both ends of said dogs, said actuation sleeve including conical inner cam surface means for pressing against the ends of said dogs to force said dogs radially inward as said actuation sleeve is moved parallel to the axis of said body member, said actuation sleeve including cylindrical inner surface means for pressing against the ends of said dogs to retain said dogs in a fixed position against said radial hub flange and against said radial sleeve flange when said dogs are at the extreme radial inward portion of their travel. 
     
     
       31. A method of remotely joining a pair of subsea flowline connectors into a fluid-tight arrangement, said method comprising the steps of: (1) forming a slot along the length of a tapered guide means,   (2) mounting a first connector in a fixed position relative to the seafloor,   (3) mounting said tapered guide means adjacent the free end of said first connector,   (4) connecting a pull-in cable to the geometric center of the free end of a second connector,   (5) lowering said pull-in cable and said free end of said second connector toward the seafloor,   (6) guiding said pull-in cable through said slot and into the geometric center of said tapered guide means,   (7) pulling the free end of said second connector toward the free end of said first connector,   (8) guiding said free end of said second connector into axial alignment with said free end of said first connector, and   (9) clamping said free end of said second connector to said free end of said first connector.   
     
     
       32. A method of remotely joining a pair of subsea flowline connectors into a fluid-tight arrangement, said method comprising the steps of: (1) mounting seals on the end of one of said flowline connectors,   (2) forming a slot along the length of an alignment funnel,   (3) mounting a first connector in a fixed position relative to the seafloor,   (4) mounting said alignment funnel adjacent the free end of said first connectors,   (5) connecting a pull-in cable to the geometric center of the free end of a second connector,   (6) lowering said pull-in cable and said free end of said second connector to the seafloor,   (7) guiding said pull-in cable through said slot into the geometric center of said alignment funnel,   (8) pulling the free end of said second connector toward the free end of said first connector,   (9) guiding said free end of said second connector into axial alignment with said free end of said first connector,   (10) clamping said free end of said second connector to said free end of said first connector, and   (11) setting the seals in a fluid-tight engagement between the ends of said first and said second connectors.